Medical instrument having actuation element movable into at least two positions

Abstract

A medical instrument includes a handle on the proximal end and a shank rotatably arranged on the handle. A tool is arranged on the distal end of the shank. This tool is rotatable relative to the shank. An actuation element is arranged on the handle. The actuation element may be moved into at least two switch positions, wherein in a first switch position the actuation element is coupled in movement to the shank and in a second switch position the actuation element is coupled in movement to the tool.

We claim: 
     
       1. A medical instrument comprising:
 a handle ( 4 ) arranged on a proximal end of the instrument, 
 a shank ( 2 ) having a longitudinal axis and rotatably arranged on the handle ( 4 ), the shank ( 2 ) being rotatable about the longitudinal axis, 
 a tool ( 6 ) arranged at a distal end of the shank ( 2 ), the tool being rotatable relative to the shank ( 2 ), 
 a shank coupling part coupled in movement to the shank ( 2 ), 
 a tool coupling part coupled in movement to the tool ( 6 ), 
 an actuation element ( 14 ) arranged on the handle ( 4 ), wherein a single component of the actuation element ( 14 ) includes a first coupling part comprising a first toothed rim ( 16   a ) comprising an outer toothing and teeth tapering in an axial direction to the shank coupling part and a second coupling part comprising a second toothed rim ( 16   b ) comprising an outer toothing and teeth tapering in an axial direction to the tool coupling part, the actuation element being axially displaceable in a direction of the longitudinal axis between at least two switch positions, the first coupling part of the actuation element forming a positive fit with the shank coupling part coupled to the shank ( 2 ) in a first switch position and the second coupling part of the actuation element forming a positive fit with the tool coupling part coupled to the tool ( 6 ) in a second switch position, wherein the single component of the actuation element is rotatable about the longitudinal axis in each of the first and second switch positions such that the single component effects movement of the shank when in the first position and effects movement of the tool when in the second position, and 
 a grip part ( 10 ) positioned proximal to the actuation element ( 14 ) along the longitudinal axis. 
 
     
     
       2. The medical instrument according to  claim 1 , wherein the actuation element ( 14 ) has a spring-biased locking element ( 52 ), which in the first switch position engages into a first peripheral annular groove ( 54 ) formed on the shank ( 2 ), and in the second switch position engages into a second peripheral annular groove ( 64 ) formed on the shank ( 2 ). 
     
     
       3. The medical instrument according to  claim 1 , further comprising a first hub ( 22 ,  68 ) having inner and outer ring sections ( 32 ,  34 ) radially spaced from one another, the first hub being arranged on the shank ( 2 ), wherein an inner side of the outer ring section ( 34 ) has a toothing corresponding to the toothing of the first toothed rim ( 16   a ). 
     
     
       4. The medical instrument according to  claim 3 , wherein the shank ( 2 ), in a region where the first hub ( 22 ,  68 ) is arranged, has an outer cross-sectional contour having at least one straight flattened section, and the first hub ( 22 ,  68 ) has an inner cross-sectional contour ( 26 ) delimited by an inner peripheral wall and corresponding to an outer cross-sectional contour of the shank ( 2 ). 
     
     
       5. The medical instrument according to  claim 1 , wherein the tool ( 6 ) is arranged on a distal end of a tube ( 8 ) guided in the shank ( 2 ) in a rotationally moveable manner, wherein a second hub ( 24 ,  78 ), having inner and outer ring sections ( 32 ,  34 ) radially spaced from one another, is arranged on the tube ( 8 ), and wherein an inner side of the outer ring section ( 34 ) has toothing corresponding to the toothing of the second toothed rim ( 16   b ). 
     
     
       6. The medical instrument according to  claim 5 , wherein in a region where the second hub ( 24 ,  78 ) is arranged on the tube ( 8 ), the tube has an outer cross-sectional contour having at least one straight, flattened section, and the second hub ( 24 ,  78 ) has an inner cross-sectional contour delimited by an inner peripheral wall ( 32 ) and corresponding to an outer cross-sectional contour of the tube ( 8 ). 
     
     
       7. The medical instrument according to  claim 1 , wherein the shank coupling part is displaceable in a displacement direction of the actuation element ( 14 ) and comprises positive fit means such that in one displacement position the shank coupling part is connectable in a rotationally fixed manner to the handle ( 4 ). 
     
     
       8. The medical instrument according to  claim 1 , wherein the tool coupling part is displaceable in a displacement direction of the actuation element ( 14 ) and comprises positive fit means such that in one displacement position the tool coupling part is connectable in a rotationally fixed manner to the handle ( 4 ). 
     
     
       9. The medical instrument according to  claim 1 , wherein the shank coupling part is not displaceable in a displacement direction of the actuation element ( 14 ) and comprises positive fit means into which a locking element ( 74 ) provided on the handle ( 4 ) engages. 
     
     
       10. The medical instrument according to  claim 1 , wherein the tool coupling part is not displaceable in a displacement direction of the actuation element ( 14 ) and comprises positive fit means into which a further locking element ( 74 ) provided on the handle engages.